The present invention relates to an intraocular lens (IOL) assembly, and more particularly, to an IOL assembly for implanting in the posterior chamber of a human eye after an extra capsular extraction.
In cataract surgery following extracapsular extraction of a cataractous lens, an intraocular lens (IOL) may be implanted. Various types of such lens, together with different implantation sites within the eye, have been proposed. It has been suggested that a lens may be implanted in the anterior chamber, the posterior chamber or in the pupilar space of an eye. Although the anterior chamber is most readily accessible for lens implantation, unless the lens is carefully sized or precisely fitted, it may not be supported at the desired angle or may otherwise traumatize the cornea. Mounting a lens within the pupilar space is also undesirable, but for different reasons. It has been discovered that while lens centering may not be a problem, the support of the lens within the pupilar space itself may be poor and/or the iris may not be dialated when desired. Because of the above disadvantages and further because the original lens is located in the posterior chamber of the eye, the posterior chamber is considered the most advantageous for IOL implantation.
While the posterior chamber is most desirable for IOL implantation, it is the most difficult and least accessible area for implementation and lens fixation. Through the development of various flexible and resilient haptic elements associated with an IOL, the problems associated with the initial implementation of an IOL in the posterior chamber of an eye have been overcome.
Even though initial IOL implementation may be successful, there are circumstances in which it would be desirable to replace the IOL initially implanted in the eye due to changes and/or deterioration in the eyes of an implant wearer, improvements in optic function (such as bifocality), and correction of unwanted refractive error. At the present, this requires removing the entire IOL implant and replacing it with a new desired implant. As will be appreciated, removing the old IOL implant and replacing it with a new one creates unneccessary trauma during surgery, in addition to the fact that it is difficult to perform.